How many meals and snacks do Brazilians eat a day? Findings from the 2017-2018 Brazilian National Dietary Survey

The habit of eating specific meals has been addressed in several studies, but the evaluation of meal patterns has received less attention. This study aimed to describe the meal patterns of the Brazilian population. A complex sampling design was used to select the 46,164 ≥ 10-year-old individuals examined in the Brazilian National Dietary Survey. Food consumption was assessed by two non-consecutive 24-hour recalls applied throughout a one-week period. The exploratory data analysis approach was used to determine the meal patterns, i.e., how individuals combined the main meals (breakfast, lunch, dinner) and snacks (morning, afternoon, evening/night) throughout the day. The most common meal patterns were three main meals + one snack, reported by 25.1% of the individuals, and three main meals + two snacks (24.6%). Other meal patterns identified were: three main meals + three snacks (18.5%); three main meals and no snacks (10.9%); one or two main meals + two snacks (7.4%); one or two main meals + one snack (6.9%); one or two main meals + three snacks (4.2%); and one or two main meals and no snacks (2.3%). Meal patterns varied according to gender and age group, and on typical versus atypical food consumption days. We found that eight patterns characterized the daily meal consumption in Brazil. Furthermore, around 80% of the population had three main meals every day and about 13% did not report having any snacks. The characterization of meal habits is important for tailoring and targeting health promotion actions.


Introduction
The study of eating occasions aims to describe some of the various aspects related to food or beverage consumption.Generally, eating occasions are categorized according to the amount and type of food consumed and to the timing of consumption 1 .Daily food consumption is usually characterized by three main meals -namely breakfast, lunch, and dinner -that can be interspersed with snacks 2,3 .
The interest in this topic is related to the role possibly played by the number and timing of meals on metabolism 4,5 , weight gain 6,7 , and insulin-related metabolic disorders 8,9 .In addition, the habit of skipping main meals and replacing them with snacks has been associated with a low-quality diet 8,9 , body adiposity 1 , cardiovascular risk 3 , noncommunicable chronic diseases 10 , and sleep disorders 11 .The daily frequency of eating occasions has been inversely associated with concentrations of total cholesterol and low-density lipoprotein cholesterol 4 and C-reactive protein 5 .Additionally, a 10-year follow-up study showed that breakfast consumption may help prevent weight gain 6 .Furthermore, the habit of eating lunch late (i.e., at 4:30 p.m.) was associated with impaired free cortisol concentrations throughout the day and reduced resting energy expenditure, fasting carbohydrate oxidation, glucose tolerance, and in the thermic effect of food 7 .
Several studies have explored the habits related to specific meals 3,8 , but few have particularly focused on the assessment of meal patterns, i.e., the combination of different eating occasions throughout the day 12 .In Brazil, local surveys have assessed the meal patterns of adolescents 13,14,15,16,17 .To date, no study with a nationally representative sample has explored the meal and snack patterns of the Brazilian population, which are addressed in this study, based on an analysis of data from the 2017-2018 Brazilian National Dietary Survey (INA).

Study design and sample
This study was based on data from the INA included in the 2017-2018 Brazilian Household Budget Survey (POF), carried out by the Brazilian Institute of Geography and Statistics (IBGE).The random sampling plan adopted in the POF is based on a master sample composed of a set of census sectors (primary sample units) stratified according to geographical area, household location (urban or rural), and household income.A subsample of households was selected by simple random sampling to form the INA sample, consisting of all residents aged 10 years or over.In the INA 2017-2018, data on food consumption were collected from 46,164 individuals from 20,112 households.The survey was carried out over a 12-month period, so that all geographic and socioeconomic strata were covered in the four quarters, allowing researchers to analyze the coverage of seasonal variation in the events 18 .

Ethics statement
This study was deemed exempt by the Research Ethics Committee of the Institute of Social Medicine, State University of Rio de Janeiro (review n. 4,316,087), under the Brazilian National Health Council Resolution n. 46/2012 and Operational Act n. 001/2013, since the data used is de-identified and publicly available (http://www.ibge.gov.br).

Food consumption assessment
Food consumption was assessed using the 24-hour diet recall (24hR) on two non-consecutive days (84% of participants responded to the second 24hR) chosen over one week.Informers were asked to report all food and beverages (including water) they had consumed the day before the household interview, which was conducted based on the Automated Multiple-Pass Method 19 , using a computational tool designed specifically for this assessment.For each food and drink, information was requested on the amount consumed, place and time of consumption, and eating occasion (breakfast, lunch, dinner, or snack) 18 .
The consumption of each meal or snack was represented by a yes-no variable.Thus, using the exploratory data analysis (EDA) 21 , meal and snack patterns were identified by combining the six eating occasions.The pattern identification and the combination algorithm were implemented in the R programing language, version 3.5.3(http://www.r-project.org).
Firstly, the individuals were classified according to whether they ate one, two or three main meals during the day.Then, the combination of the main meals with the morning, afternoon, and evening snacks resulted in the combinations of one, two, or three main meals with none, one, two, or three snacks.Of the 64 possible combinations, eight included three main meals, 24 included two main meals, 24 only included only one main meal, and eight did not include any main meals.The latter were disregarded, as their frequencies were negligible (0.1%).Box 1 shows the 56 possible combinations considered and used to identify the meal and snack patterns.These combinations were classified into broad categories considering the number of main meals and snacks consumed in one day.Then, the categories including one and two main meals were aggregated.The final eight meal patterns were defined based on their interpretability and the frequency with which they were reported by the population.The same process was applied to data collected during days 1 and 2 of the 24hR, and as no differences were found between the meal patterns identified during these two days (Supplementary Material: https://cadernos.ensp.fiocruz.br/static//arquivo/suppl-e00009923_5505.pdf),only data from the first 24hR were reported.

Statistical analyses
The proportion (and 95% confidence intervals [95%CI]) of individuals with each meal and snack pattern was estimated according to gender, age group (adolescents: 10-19 years old; adults: 20-59 years old; and older adults: ≥ 60 years old), and food consumption day (typical or atypical).This information was provided by the participants at the end of the 24hR.Non-overlapping 95%CI indicated differences in the proportions across the categories of explanatory variables.The analysis considered the sample weights and the effect of the study design using the Complex Sample module of the SPSS, version 19 (https://www.ibm.com/).

Results
In total, 52.1% of the study participants were women, 17.8% were adolescents, 64.6% were adults, and 17.6% were older adults.A total of 88.8% of the study population reported having a typical day of food consumption (Tables 1 and 2).
The comparison of the distribution of meal and snack patterns according to typical and atypical food consumption days showed that the patterns that included the three main meals were more frequent on typical days (81.3%) than on atypical days (60.8%).The opposite was observed for all the patterns that included one or two main meals, which were more frequent on atypical days (38.3%) than on typical days (18.6%).The most important differences between typical and atypical food consumption days were found for the patterns "one or two main meals + two snacks" (6.5% vs. 14.5%),"three main meals + three snacks" (19.2% vs. 12.3%), and "three main meals + one snack" (25.8% vs. 19.4%)(Table 1  Patterns including three main meals were more frequent among men (80.5%) than among women (77.9%) and less reported by adolescents (75.1%) than by adults (79.8%) and older adults (80.9%).The meal and snack pattern most frequently reported by men, adolescents, and adults was "three meals + one snack", and the most frequent pattern among women and older adults was "three meals + two snacks".A meal consumption pattern including one or two main meals was reported by 24.9% of adolescents, a proportion greater than that found for adults (20.2%) and older adults (19%) (Table 2).
The greatest differences between men and women were found for the set of meal and snack patterns including at least one snack.These patterns were more frequently reported by women (88.2%) than by men (85%).The "three main meals" pattern and the remaining patterns including three main meals were both more frequent among men than women (12.4% vs. 9.6% and 80.6% vs. 77.8%,respectively) (Table 1).
The most important differences between age groups were observed for the set of patterns including one or two main meals, which were more frequently reported by adolescents (24.9%) than by adults (20.2%) and older adults (19%).On the other hand, the patterns including three main meals were more commonly reported by older adults (80.9%) and adults (79.8%) than by adolescents (75%).Lastly, it became evident that older adults had at least one snack between their daily meals more frequently than adults (88.6% vs. 85.7%)(Table 2).

Discussion
Eight patterns of daily meal and snack consumption were identified in the analysis of the INA 2017-2018.Generally, the three main meals -breakfast, lunch, and dinner -were part of the daily eating habits of approximately 80% of participants, and the consumption of at least one snack throughout the day was reported by 87% of the Brazilian population.In the present study, it was found that 80% of Brazilians had a meal pattern compatible with the recommendations on meal habits offered by the Dietary Guidelines for the Brazilian Population 2 .However, alternative meal patterns were also observed in the population: about one fifth of participants reported skipping at least one main meal per day, a proportion that almost doubled on atypical days and was more evident among women and adolescents.
Cad. Saúde Pública 2024; 40(2):e00009923 In this study, the principle of parsimony 22 was followed to choose an objective approach -the EDA 21 -to examine meal and snack patterns, which were derived from the combinations of meals and/or snacks according to their consumption by participants in specific days.This helped avoid arbitrariness, eliminating events such as the determination of the number of dimensions proper of the multiple correspondence analysis 23 or the number of clusters generated by k-means clustering 24 .Moreover, patterns generated by correspondence analysis or clustering can be difficult to interpret 25 .Additionally, Leech et al. 26 highlight that the techniques for identifying meal patterns guided by exploratory data analysis have advantages over approaches based on hypotheses that only consider the time of consumption of meals, as they allow for the observation of different eating habits in different segments of the population, including less conventional meal patterns.
A recent narrative review found that the principal component analysis, clustering, latent class analysis, and decision trees were the most commonly used statistical techniques to identify meal patterns in observational studies 12 .The authors pointed out that meal patterns can be grouped into three categories: (i) temporal patterns, referring to the timing and distribution of meals throughout the day; (ii) content patterns, referring to the combinations of foods within each meal and combinations of meals over the day; and (iii) context patterns, referring to external elements of the meal, such as location, activities done while eating, and the presence or absence of other people.O'Hara & Gibney 12 observed that the most common temporal meal patterns were the three meals per day pattern, the breakfast skipping pattern, and a grazing pattern consisting of smaller but more frequent meals.Likewise, in our analysis, temporal meal patterns were identified and the patterns including three main daily meals were found to be the most common.
In the INA 2017-2018, the elevated presence of meal and snack patterns that did not include the three main meals may have resulted from the changes in eating habits owing to the nutrition transition process that had taken place over the last decades 27 , which ultimately resulted in reduced time for cooking and eating at home and in increases in the consumption of packaged, ready-to-eat products as well as the habit of eating away from home 28,29 .Additionally, meal and snack patterns including one or two main meals were found to be more frequent on atypical food consumption days.Atypical food consumption days are characterized by non-habitual consumption -days like these include weekends, celebrations, festive dates, sick days, and other events causing changes in the daily routine -, while typical food consumption days reflect the individual's eating routine, i.e., in these days, consumption is closer to usual 30,31,32 .
Differences in the definition of eating occasions may affect how meal patterns are characterized and the direction and magnitude of associations with diet quality and health outcomes 26,33 .Leech et al. 26 identified the eight most commonly used definitions to describe eating occasions, and the ones employed most frequently considered the time of day and the designation of the respondent or identified participant.Due to the fact that there are multiple ways to define eating occasions, studies on this subject usually detail the criteria used to classify consumption occasions 34 .In this study, eating occasions were designated by participants when answering a 24hR, and snacks were classified as morning, afternoon, or evening snacks according to the time of day when they were consumed.
Similar to the present study, in the third National Health and Nutrition Examination Survey, Kerver et al. 35 used participant-identified meal and snack patterns of U.S. adults based on meal and snack/ beverage consumption occasions reported in a 24hR.The authors used the five most reported meal and snack combinations to identify the meal patterns, which were divided into the following categories: breakfast + lunch + dinner + two or more snacks (31.6%); breakfast + lunch + dinner + one snack (15.4%); breakfast + dinner + two or more snacks (13.1%); breakfast + lunch + dinner (8.3%); and lunch + dinner + two or more snacks (7.6%).The authors emphasized that meal patterns including the main meals may be associated with diets with better nutritional quality, since individuals who reported the patterns breakfast + lunch + dinner + two or more snacks and breakfast + lunch + dinner + one snack had the highest intakes of all micronutrients examined, except cholesterol, vitamin B 6 , and sodium 35 .
In the Santé, Inégalités et Ruptures Sociales survey (SIRS -Health, Inequalities and Social Ruptures), conducted with the adult population of the metropolitan area of Paris (France), Lhuissier et al. 36 identified meal patterns by asking three questions: (i) how many times do you eat during the day?; (ii) how many of these eating occasions do you consider as meals?; and (iii) what are your meal times during the day?The authors observed that, similar to the findings of this study, the three-meal pattern Cad.Saúde Pública 2024; 40(2):e00009923 was as a strong cultural trait (65.9%) and was more frequent among older individuals (60 years old and over: 77.4%) compared to younger ones (18-29 years old: 54.9%).Furthermore, it appears that the practice of having three main meals a day is more common in Brazil than in Paris.Additionally, while in Brazil men were found to adopt the three-meal pattern more frequently than women, in Paris, the three-meal pattern was more common among women (70.5%) compared to men (60.7%).
In Brazil, meal and snack patterns have been evaluated in studies with adolescents, and most information on meals was obtained using self-administered, close-ended questionnaires about the usual frequency of meals; additionally, meal habits were classified as satisfactory or unsatisfactory depending on whether the main meals (breakfast, lunch, and dinner) were regularly or irregularly consumed 13,15,16,17 .The present study adds important contributions to the knowledge on this subject in Brazil, as it expands the identification of meal consumption patterns to other age groups, such as adults and older adults.Furthermore, in addition to relying on the respondent's designation to characterize the meals, this analysis used an exploratory statistical approach to identify the possible daily combinations of meals and snacks and recognize the meal patterns that represent the eating occasions in Brazilians' routines.
The possible limitations of this study are related to the fact that the 24hR was used to obtain information on meal and snack habits.The 24hR allows researchers to obtain detailed information on food consumption, including the composition and time of consumption of meals and snacks 26,35 , but it relies on the respondents' memory and may be subject to underreporting.In the INA 2017-2018, strategies to reduce misreport included following the Automated Multiple-Pass Method 19 to apply the 24hR with the support of computational resources.Moreover, as the 24hR is not associated with systematic errors, it is often used in extensive population-based surveys carried out worldwide 37 .Furthermore, each participant informed whether the reported food consumption corresponded to a typical or an atypical food consumption day.Lastly, the analyses showed that there were no significant differences between the meal and snack patterns identified in the first and the second 24hR.
One strength of this study is its large, nationally representative sample, which included Brazilians aged 10 years and over and provided robust estimates.In addition, the eating occasions were identified objectively, based on participants' designation and the time of consumption.Another strong point of this study is the fact that it took a holistic approach to meal and snack habits rather than focusing on isolated meals, which made it possible to assess participants' compliance with dietary recommendations and to identify alternative meal and snack patterns.This approach allows future studies to explore the association between dietary habits and health outcomes, an aspect that has been highlighted by chrono-nutrition studies 38 .
Traditionally, nutritional epidemiology research has focused on the assessment of dietary intake and patterns; however, the focus on dietary habits is still restricted 26 , especially in low-and middleincome countries such as Brazil.As pointed out by Popkin & Ng 39 , the process of nutritional transition, which takes place more rapidly in middle and low-income countries than in developed ones, includes changes in eating habits, for example, an increase in the number of eating occasions and in the contribution of ultra-processed products to total energy intake.Various studies have indicated that the frequency, location, and nutritional composition of main meals and snacks are associated with diet quality and health 12 .Moreover, specific meal patterns may be associated with better diet quality and nutrient intake, considering that these patterns may reflect healthier lifestyle choices 35 .In Brazil, Rodrigues et al. 16 carried out a cross-sectional school-based study to evaluate the quality of adolescents' diets and observed that the habit of skipping meals was associated with diets of low nutritional quality, especially those with low consumption of fruits and vegetables and high consumption of solid fats, added sugar, and alcoholic beverages.Therefore, acknowledging meal consumption patterns is central for targeting and tailoring actions to promote healthy eating.
These findings may be an initial step towards the recognition of meal and snack habits in Brazil.Further studies should assess the socioeconomic and demographic characteristics associated with each meal and snack pattern, as well as the distribution of energy intake and other dietary features specific to these patterns.

POSSIBLE COMBINATIONS COMBINATIONS OF MAIN MEALS AND SNACKS (n = 56) BROAD CATEGORIES OF MEAL AND SNACK PATTERNS (n = 12) IDENTIFIED MEAL AND SNACK PATTERNS (n = 8)
Possible combinations * of main meals and snacks and identified meal consumption patterns.Brazilian National Dietary Survey, 2017-2018.

Table 1 Distribution
(%) of the population according to meal and snack patterns by typical or atypical days of food consumption.Brazilian National Dietary Survey, 2017-2018 (n = 46,164).* Combinations that did not include any main meals (n = 8) were not considered.Cad.Saúde Pública 2024; 40(2):e00009923

Table 2
Distribution (%) of the population according to meal and snack patterns by sex and age group.Brazilian National Dietary Survey, 2017-2018 (n = 46,164).